Oil-well swab



NOtV. 251

n.. ROBINSON OIL WELL SWAB Filed Dec. 9, 192] 2 Sheets-Sheet. l

venten .v ROBINSON OIL WELL SWAB Filed DEC. 9, 1921 2 Sheets-Sheet 2 Patented Nov. 25, i924.

ATENT OFFICE.

LUTHER ROBINSONOF ELDORADO, KANSAS.

OIL-WELL swan.

Application filed December 9, 1921.

To all whom t may concern:

Be it known that I, LUTHER ROBINSON,

a citizen of the United States, residing at Eldorado, in the county of Butler and State of Kansas, have invented certain new and useful Improvements in Oil-Tell Swabs;

and I do declare the following to be a full.

clear, and exact description of the invention,

such as will enable ot-hers skilled in the art l0 to which it appertains to make and use the same, reference being had to the accompanying drawings and to the figures of reference marked thereon, which form a part of this specification.

This invention relates to oil well swabs and particularly to a novel construction of swab in-which oil may be introduced into the swab and trapped therein for removal from the well,there being means provided for unloading the oil from the swab when the columnA of oil'withinthe well is greater than the capacity of the elevating means for raising it.

I have also provided means whereby the maximum 'depth below the surface of the oil at which ,thev swab will be effective can be regulated.` V

I have. provided means whereby a packing or piston for raising the oil may be conveniently lowered within the well, the piston being supported by a tubular member having a substantially unobstructed through port whereby the oil may kpassthrough it to the top of the piston or packing to be raised; the construction also being such that upon the raising of the pist-on, the supply port will bek closed, and in the'event that the swab is overloaded, a novel form of unloading valve will release the excess oil and to this end I have provided means whereby the unloading valve'can be set to operate at any point below'the surface of the column of oil within the oil well casing.

The particular novelty of my invention, as well as its method of operation, will be apparent by reference-'to the following de 'scription in connection with; the accompanying drawings, in which- Fig. 1 isa perspective view of a swab constructed in accordance with my invention, showing the passage of the same through the well casing.-

Fig. 2 is a similarV view showing the parts in position when the swab is about to be Serial No. 521,096.

raised, part of the upper casing member being broken away to show the top of the lower casing member.'

F ig. 3 is ak vertical, longitudinal, sectional view through the swab, the elevating stem being shown in elevation, and

Fig. 4 isa vertical, longitudinal, sectional view of a slightly modified form of piston or packing, part of the lower casing member being shown in elevation.

Referring now to the drawings by numerals of reference:

1 designates a stem, at the upper end of which is a tool coupling 2, whereby the stem can be attached to the tool to be lowered into the well. rI`he lower end of the stem 1 is connected to perforate cap member 3 having a plurality of openings l therein, surrounding the threaded opening 5, to which the lower end of the stem 1 is screwed., there being preferably a lock nut 6 to se cure thecap to the stem, as shown.

The cap 3 is provided with an internally threaded 'iiange 7, which engages the external threads 8 on the lower casing member or tube 9, having a valve seat 10 at its lower end, rIhe exterior of the lower portion of the tube is threaded, as at 11, to receive an adjust-able collar 12, upon which may rest one end of an expansion spring 13, the other end of the spring bearing against the end wall 14 of a reciprocatory cage 15.

The cage 15 is sleeved over the lower end of the casing member 9 and extends beyond the ring 12 so as to support a plug valve 16, which may be seated upon the seat 10 due to the expansive force of the spring 13. It is obvious that the spring may be loaded by turning the ring 12 so that the valve 16 can unseat only upony a determined pressure within the chamber 17 of the lower casing member 9.

As will be-seen by reference to the drawings, the cap member 3 constitutes a cover for the upper end of the lower casing member 9 so that liquid, such as oil and the like, can enter only through the openings or ports 4L. Thereis a longitudinally reciprocatory valving member for normally closing o communication betweenv .the well and the chamber 17. The valving member constitutes the upper casing member 18, having groups 19 and 2O of spider arms, the ends of which slide on the stem 'l and center the sleeve or upper casing member 18 with respect thereto.

The sleeve or upper casing member 18 carries a valve ring 21, which is approximately the saine diameter as the cap 3 so that when the valve ring is seated upon the cap 3, communication between the well easing and the chamber 17 will be cut ofi; but when the valve ring is raised, communication may loe had between the exterior of the casing 9 and the chamber 17.

The sleeve 18 has a central unobstructed passage except for the groups 19 and 20 of guide fins or spider arms, and it carries plston rubbers or packers comprising rings 22 and 23, spaced apart by a metal ring 24 sleeved upon the sleeve 18. rlhe rubber rings 22 and 23 are clamped between the ring 24 and certain loclr nuts or collars.

Atthe upper portion of the sleeve are threads 25 to receive the lock collars or washers 26 and 27, which may be screwed down upon the collar 22 to firmly clamp it between the lock collar 2G and the partition ring 24. On the lower end of the sleeve 18 is a similar' threaded portion 28 to receive the lock collars or washers 29 and 30, adjustable in a direction opposite to the adjustment for the collars 26 and 27 whereby the ring 23 can be clamped between the partition ring or collar 241 and the lock washers 29 and 30.

The rings 22 and 23 constitute piston rings adapted to lie flush against the inner wall of the well casing so that they will constitute in effect pump pistons for raising the oil above them.

l'hen the parts are assembled, the friction of the perimeters of the piston rings 22 and 23 against the inner wall of the pump casing will cause a frictional retarda tion of the upper casing member or sleeve 18 so that the lower casing member 9 will move away therefrom, as shown in Fig. 1, exposing the holes or orifices 4 in the cap 3 and also exposing the lower open end 31 of the sleeve 18, the upper end 32 of the sleeve 18 also being unobstructed except by the fins or spider arms 19. Therefore, when the swab is lowered below the oil level, the oil will pass unobstructed upwardly through the hollow portion of the sleeve 18 so there willbe no appreciable retardation of the .swab in its descent, the port. area of the hollow portion of the sleeve 18 being sufficient to allow a free flow of the oil above the piston formed by the sleeve and the rings 22 and lvhen the swab has been lowered a suiiicient distance below the oil level, it will be raised. The first movement will be that the stem 1 will start to rise while the piston is held frictionally stationary and as the stem rises, it will carry with it the mem ber 9, which will abut againstthe lower face of the ring 21 and close olf communication :naief/ei of the oil above the piston with the space below the piston. The swab will then startto ascend with the parts arranged as shown in Figs. 2 and 3.

As the swab moves upwardly, it will lift the oil above it within the oil well easing unless the weight of the oil preponderates over the scale of the spring. ln whichevent the weight of the oil will oppose the tendency of the spring to seat the valve 16 so the valve will become unseated and the swab will be unloaded of its overload. As soon as the weight of the oil is such that it cannot preponderate over the spring, the spring will close the valve and it is apparent that by turning the collar 12, the spring can be adjusted for any determined pressure so that it will unload whenever the swab is beyond the maximum depth below the surface of the oil at which the springhas been set.

In Fig. 4 l have shown the same generic embodiment of my invention with a slightly modified form of piston ring. Un the sleeve or upper casing member 18 is a plurality of beveled rings 33, supporting piston rings Sel with beveled faces 3:3, adapted to ride on the rings The rings Sel are split rings and the meeting ends of one ring overlap or are offset with respect to the meeting ends of an adjacent ring so that there will be no leakage between the rings. It will be seen, therefore, that when the operator aises the stem 1, he will cause the inclined faces of the rings 33 to ride on the inner inclined faces of the rings 34 and expand them against the inner wall of the oil well casing. 1t is to be understood that I do not lay any claim to the .specific form of the expansible rings shown in Fig. e but have illustrated them solely to indicate that such constructions can be employed in connection with my present invention and without violating any of thel principles thereof.

lVhat I claim and desire to secure by Letters-Patent is:

-1. An oil well swab comprising a stem, an open ended tube longitudinally slidable on said stem, a piston ring carried by the tube intermediate its ends, the dia-meter of the piston ring being greater than the diameter of the tube whereby the ring constitutes a piston, a tubular member supported by the stem against the upper end of which the tube may rest to close the lower end thereof, and a normally seated overload valve for closing one end of the tubular cylindrical member, said valve unseating in response to the weight of the oil above it.

2. An oil well swab comprising a stem, an open ended tube longitudinally slidable on said stem, a piston ring carried by the tube intermediate its ends, the diameter of the piston ring being greater than the diameter of the tube whereby the ring constitutes a piston, a tubular Cylindrical member supported by the. stem, against the upper end of which the tube may rest to close the lower end thereof, and a spring-seated valve for normally closing one end of the tubular cylindrical member.

3. An oil well swab comprising a stem, an open ended tube longitudinally slidable on said stem, a pist-on ring Carried by the tube intermediate. its ends, the diameter or the piston ring being greater than the diameter of the tube whereby the ring constitutes a piston, a. tubular cylindrical member supported by the ste-m, against the upper end of which the tube may rest to close the lower end thereof, a spring-seated valve for normally closing one end of the cylindrioal member, and means for adjusting the tension of the spring.

4. An oil well swab comprising a stem, an open ended tube longitudinally slidab-le on said stem, a piston ring carried by the tube intermediate its ends, the diameter of the piston ring being greater than the diameter of the tube whereby the ring constitutes a piston, a tubular cylindrical member supported by the stem, against the upper end of which the tube may rest to close the lower end thereof, and an overload valve normally closing one end ot' the cylindrical member.

5. An oil well swab comprising a stem, a tubular Cylindrical member at the lower end of the stem, the upper end of the cylindrical member having a perforate cap, a normally closed, overload relief valve in the bottom of the cylindrical member, a sleeve mounted upon the stem and movable toward and away from the cylindrical member, and a piston ring about the perimeter of the sleeve, the perimeter of the piston ring be ing spaced away from the sleeve due to the thickness of the ring.

6. An oil well swab comprising a guide, a longitudinally movable, open ended tube carried by the guide, a ring piston carried by the perimeter of the tube and interposed between the ends thereof, a tubular tubesupporting member on the end of the guide constituting a Valve for the lower end of l the tube member, and an overload relief valve carried by 'the tube supporting member.

In testimony whereof I affix my signa ture.

LUTHER ROBINSON. 

